The electrostatic dust collector of prior art comprises a dust charging section and a dust collecting section, wherein said dust charging section comprises a plurality of wires applied with high voltage and a counter-electrode which is made up of paralleled wires or plates, and said dust collecting section comprises positive electrodes and negative electrodes disposed alternately. Ionizing air in dust charging section so that dust particles in the air are charged, then the charged dust particles are attracted onto corresponding electrodes by the electric field force in the dust collecting section; as a result, dust particles are separated from the air. By electrostatic dust collecting technology, the force for separating dust particles directly works on the dust particles themselves, therefore, compared with filter dust collectors or other types of dust collectors, electrostatic dust collectors are more widely applicable to different sizes of dust particles from the largest scores of microns to the smallest 0.001 microns with the lowest power consumption and the minimum air flow resistance.
However, the efficiencies of prior art electrostatic dust collectors are generally low, particular to tiny dust particles, due to the following reasons: the ionizing voltage applied in dust charging section can not be too high because of the limit by corona current, otherwise the ozone concentration is likely to exceed standards, thus the applied voltage in dust charging section is relatively low, and dust particles are not charged sufficiently; the electric field intensity between metal electrodes is limited in consideration of air breakdown or disruptive discharge, thus Coulomb forces by charged electrodes on tiny dust particles are weak, and dust particles are not easily attracted onto the corresponding electrodes with limited air flow strength.